1. Field of the Invention
The present invention relates to ground-fault circuit interrupter (GFCI) devices, and more particularly relates to an improved GFCI device with a reverse wiring protection function and a circuit condition detection function.
2. Description of the Related Art
To ensure the safety of home electrical appliances and other electrical devices, ground-fault circuit interrupters (GFCI) with a reverse wiring protection function and circuit leakage current protection function have been introduced. U.S. Pat. No. 7,019,952 (based on China utility model application), which is incorporated by reference in its entirety, describes a GFCI device. In this device, if the GFCI is incorrectly wired, i.e., if the line power is connected to the output side of the GFCI, the GFCI can prevent the electrical connection between the output side and the input side as well as between the output side and the output plugs, so that no power is outputted to the output side or the plug. Only when the GFCI is correctly wired, i.e., when the line power is connected to the input side of the GFCI, can the device electrically connect the input side with the output side and the output plugs.
Although conventional GFCI devices have a reverse wiring protection function, these devices may lose is leakage current protection function under certain conditions, such as when the leakage current amplifying circuit (IC) is not property functioning. These cause hidden safety problems. Therefore, it is desired to provide GFCI devices that have a circuit condition detection function.